1. Field of the Invention
The invention relates in general to articles of footwear for animals and, in particular, to a horse boot with a cupped sole.
2. Description of the Prior Art
Horse boots are used to protect the hooves and fetlocks of horses and are sometimes used in lieu of horseshoes. A horse boot typically consists of a shell that includes a sole with opposed flat, top and bottom, major surfaces and an upper that projects upward from the top surface and forms an enclosure for the hoof and sometime also for a portion of the fetlock of the horse. The shell is commonly of unitary construction, the upper typically extending along the rim of the sole and having an edge integral with or secured to the sole. A second top edge of the upper is remote from the sole and is often connected to a cuff that can be tightened around the hoof and pastern of the horse.
The upper of the shell and the cuff are spread open in order to put the boot on the hoof of the horse. After spreading the upper and the cuff, the boot is slid over the hoof and the cuff is tightened around the pastern to secure the boot in place. The shell is similarly tightened around the hoof in various manners, such as with buckles, elastic restraining devices, or even by gluing the inner surface of the shell to the hoof.
The objective of these various securing means has been to provide a tighter and more secure fit over the hoof of the horse to avoid movement of the boot with respect to the hoof. As a result, the boot is less likely to chafe the hoof or to come off, but it also forms a rigid enclosure that prevents some of the hoof's physiological functions. The hoof of a horse includes two main parts known as the frog and the sole, respectively. The frog is a softer inner portion of the hoof surrounded by the harder sole at the bottom of the hoof. The two together function to provide a pumping action that enhances blood circulation. In bootless wild horses, the frog is always bearing weight because it contacts the ground at each step, a condition that cannot be reproduced with rigid boots with a flat upper sole surface. It is well known that the free hoof expands when it meets the ground and it contracts when it is raised off the ground. This repeated expansion and contraction of the hoof produces a corresponding motion in the frog that has the physiological effect of supplementing blood circulation in the hoof and the lower leg of the horse. The fit of prior-art boots does not account for the shape of the underside of the hoof and for the natural deformation it experiences during riding.
In order to ameliorate the effect of the boot sole on the hoof, cushioning pads have been used as inserts designed to conform to the frog of the hoof. These pads are compression fit or otherwise secured to the top surface of the boot's sole and vary in hardness and resilience. In all cases, they represent a filling structure designed to support the frog but with sufficient resilience to allow its natural contraction and expansion resulting from the horse's gait. Therefore, the efficacy of these pads is based on having the appropriate balance between support and give to try to match the natural environment to which a bootless hoof is exposed. This is impossible to achieve because optimal support and give through pads would necessarily require changes to accommodate different riding conditions and terrain.
Another problem associated with prior-art boot shells is the fact that the width of the sole is fixed, as determined by the size of the boot. Therefore, a tight boot cannot accommodate in any manner the hoof's radial expansion that is associated with the pressure exerted on it by the ground at each step. That is, when the hoof meets the ground, the perimeter (most notably the width) of the hoof tends to expand slightly; when the hoof is lifted, it returns to its un-deformed contracted condition. Thus, if the shell of the boot is selected for a tight fit (which is always the case to ensure stability and prevent abrasion), the shell constrains the hoof to a condition under weight that does not allow its natural expansion/contraction cycle.
This invention is directed at providing a solution to both problems. Specifically, the invention is directed at providing a horse boot with a sole that supports the frog at all times while permitting both its natural motion and the lateral expansion/contraction of the hoof's sole.